EP4013990A1

EP4013990A1 - Pipe leadthrough module for a cryogenic container

Info

Publication number: EP4013990A1
Application number: EP20760374.7A
Authority: EP
Inventors: Matthias Rebernik
Original assignee: Cryoshelter GmbH
Current assignee: Cryoshelter Lh2 GmbH
Priority date: 2019-08-14
Filing date: 2020-08-12
Publication date: 2022-06-22
Also published as: US20220275910A1; CO2022001617A2; AU2020331403A1; CA3146907A1; WO2021026581A1

Abstract

The invention relates to a pipe leadthrough module (7) for a cryogenic container (1) that has an inner tank (2) and an outer container (3) vacuum-isolated with respect to the inner tank, wherein the pipe leadthrough module (7) comprises a casing pipe (6) and a pipeline (5) at least partially accommodated in the casing pipe (6), wherein a first pipeline end (10) of the pipeline (5) passes through a first casing pipe end (8) of the casing pipe (6) such that the first pipeline end (10) can be rigidly connected to the outer container (3) and the first casing pipe end (8) can be rigidly connected to the inner tank (2), the pipeline (5) and the casing pipe (6) being rigidly connected to one another at a second casing pipe end (13), and the pipeline (5) and the casing pipe (6) each having a bend (17, 18) in a region between the first casing pipe end (8) and the second casing pipe end (13).

Description

Tube feed-through module for a cryocontainer

The invention relates to a pipe lead-through module for a cryogenic container, which has an inner tank and an outer container that is vacuum-insulated with respect to this, the pipe lead-through module comprising a casing tube and a pipeline at least partially received in the casing tube.

According to the prior art, liquefied gases can be stored in containers (“cryogenic containers”) in order to store them as fuel for an engine, for example. Liquefied gases are gases that are in a liquid state at boiling point, the boiling point of this fluid being pressure-dependent. If such a cryogenic liquid is filled into a cryocontainer, then, apart from thermal interactions with the cryocontainer itself, a pressure corresponding to the boiling temperature is established.

Since the fluid stored in the cryocontainer is at a temperature which is significantly lower than the ambient temperature of the cryocontainer, it must be designed accordingly in order to reduce heat transfers that occur. For this purpose, it is known from the prior art to design cryocontainers as double-walled tanks which have an inner tank and an outer container. The inner tank is accommodated in the outer container and thermally insulated from it, for example in that there is a vacuum between the inner tank and the outer container.

In these embodiments, it should be noted in particular that thermal changes in length of the inner tank and outer container, which occur in different operating states of the container, must be compensated for. It is therefore desirable to have operational stability despite the mechanical changes in length and vibrations during operation.

Pipe guides between the inner tank and the outer container, for example to fill the inner tank or to remove fluid from the inner tank, are particularly critical here. Due to the thermal changes in length, the pipeline guides must therefore be designed to enable the inner tank and the outer container to slide into one another. For pipe penetrations with a passage in the area of the cylinder jacket of the cryogenic container, the assembly of the inner tank with the pipe penetrations already installed in the outer container can be made possible, i.e. the protrusion over the cylinder jacket of the inner tank can be selected to be smaller than the inner diameter of the outer container, at least at the time of Assembly.

It is therefore an object of the invention to create a pipe lead-through module which can absorb thermal changes in length of the inner tank and the outer container particularly well.

This goal is achieved by a pipe lead-through module for a cryogenic container, which has an inner tank and an outer tank that is vacuum-insulated with respect to this, the pipe lead-through module comprising a casing tube and a pipe at least partially received in the casing pipe, the pipe line being able to be passed through a first casing pipe end of the casing pipe so that the first end of the pipe can be rigidly connected to the outer container and the first end of the cladding tube can be rigidly connected to the inner tank, the cladding tube and the pipeline being rigidly connected to one another at a second cladding tube end, the cladding tube and the pipeline each having a kink in an area between the first and the have the second cladding tube end.

The kink in the pipeline within the cladding tube enables the pipeline to have more leeway within the cladding tube in the event of thermal changes in length than is the case with linear tube feed-through modules. Thermal changes in length of the inner tank and the outer tank can therefore be effectively compensated with the present pipe penetration module. In addition, the kink enables the pipeline to be pulled further out of the cladding tube, e.g. by at least a wall thickness of the outer container, in order to simplify the welding with the pipeline to the outer tank.

The kink in the cladding tube and in the pipeline also allows vibrations of the outer container to be better compensated so that they are not transmitted to the inner tank. Furthermore, the connection of the cladding tube to the inner tank or the pipeline to the outer container is easy to produce and can be realized, for example, by an automatable weld seam.

Another advantage of the solution according to the invention is that no reinforcement of the inner tank is required, so that small diameters of the connecting pieces are achieved which means that the cryocontainer can be manufactured in compliance with the guidelines. Last but not least, the kink achieves a flexible construction of the compensation module, whereby a tolerance compensation is achieved for all individual, component and assembly tolerances that come together during assembly.

It is advantageous if the kinks are designed such that a first section of the cladding tube or the pipeline at an angle of 30 ° to 150 °, preferably from 70 ° to 110 °, particularly preferably 90 °, to a second section of the cladding tube or . the pipeline is located. Although it is preferred if the bend is 90 °, since this significantly simplifies the structure of the compensation module, bend angles that differ from this are also possible in order to achieve the advantages explained above.

It is particularly preferred if the pipeline or the jacket tube is more flexible over at least one functional section than outside the functional section. As a result, an improved compensation of the thermal changes in length can be achieved through a favorable distribution of the mechanical stresses. If the functional section is provided on the pipeline, the functional section is preferably at least partially within the cladding tube. This can be realized in particular by the following embodiments.

According to one embodiment, it is preferred if the pipeline has a thinner wall thickness over at least one functional section than outside the functional section, the functional section being at least partially inside the cladding tube. Alternatively, the pipeline can be designed as a bellows tube over at least one functional section, the functional section being at least partially within the cladding tube. Depending on the embodiment, the functional section can also be located completely within the cladding tube.

Both of the named embodiments have the advantage that the thinning of the pipe wall thickness or the design as a bellows tube results in a further improved compensation of the thermal changes in length through a favorable distribution of the mechanical stresses. Furthermore, the measures mentioned can avoid the concentration of the increased mechanical stresses on the end areas of the pipeline at which the cladding tube is connected to the inner tank (both at the first cladding tube end and - optionally - at the second cladding tube end) and the pipeline is connected to the outer container are. In further embodiments it can also be provided that the cladding tube has a thinner wall thickness over at least one functional section than outside the functional section, or the cladding tube is designed as a bellows tube over at least one functional section. In these embodiments it is particularly preferred if the functional section is spanned by an axial stiffener. For example, two stiffening rods running parallel to the cladding tube, which are located on opposite sides of the cladding tube, can be used as axial reinforcement. This allows, on the one hand, a radial kinking or bending of the cladding tube between the stiffening rods and, on the other hand, a compression of the cladding tube in the axial direction is still prevented.

In order to facilitate the attachment of the pipe feed-through module to the cryocontainer, it can be provided that the pipe has a welding socket at the first pipe end for connection to the outer container and / or the jacket pipe has a stiffening ring on the first jacket pipe end for connection to the inner tank. As a result, the individual components can be connected in particular with automated weld seams, since the welding socket or the stiffening ring are particularly suitable for these purposes.

It is also preferred if the cladding tube has an end plate at the second cladding tube end for connection to the inner tank. As a result, the cladding tube can advantageously also be connected to the inner tank at the second cladding tube end, whereby the cladding tube can be rigidly connected to the inner tank at both ends. The purpose of this is to make it more difficult for vibrations of the pipeline to set the cladding tube into resonance oscillation.

In a further embodiment, the pipeline can be equipped with an internal thread at the first pipeline end. This enables the pipe end to be pulled out of the pipe lead-through module in a simplified manner, as a result of which a welded connection to the outer container can be made more easily.

In the assembled state, the invention consequently relates to a cryogenic container, comprising an inner tank, an outer container that is vacuum-insulated with respect to the inner tank, and a pipe feed-through module according to one of the aforementioned embodiments, the cladding tube protruding into the inner tank. On the one hand, the pipeline protrudes into the inner tank, but on the other hand also protrudes out of the inner tank, where it is connected to the outer container. In a particularly preferred embodiment, the pipe lead-through module is connected to the cryocontainer in such a way that the pipe lead-through module acts as a thermal siphon in an operating position of the cryocontainer. According to the invention, the kink therefore not only has the function of compensating for thermal changes in length, but also makes it possible, through the siphon effect, to avoid thermal bridges between the inner tank and the outer container. This is achieved because the evaporation of the liquid phase creates a gas cushion at the warm end of the line that cannot go back into the inner tank, which prevents the liquid phase from flowing in. The heat input can therefore be reduced to an acceptable level. The specific installation position of the pipe feed-through module in order to achieve the effect as a thermal siphon is at the discretion of the specialist.

Advantageous and non-limiting embodiments of the invention are explained in more detail below with reference to the drawings.

FIG. 1 shows a cryocontainer with three pipe feed-through modules according to the invention. FIG. 2 shows one of the pipe lead-through modules from FIG. 1 in detail.

FIG. 3a shows a cryocontainer with a thermal siphon according to the prior art and FIG. 3b shows a detail of FIG. 3a.

FIG. 4 shows an alternative embodiment of the pipe feed-through module from FIG.

FIG. 1 shows a cryogenic container 1, which has an inner tank 2 and an outer container 3 which is vacuum-insulated with respect to this. The fluid 4 stored in the cryocontainer 1 is, for example, liquefied natural gas, also known to the person skilled in the art as LNG (“Liquid Natural Gas”). In the example shown, the fluid 4 is in liquid form up to a level F, above it in the gaseous state. The cryocontainer 1 is usually carried on a motor vehicle, in which case the fluid 4 is used as fuel for an engine of the motor vehicle.

In order to introduce fluid 4 into the cryocontainer 1 or to remove fluid 4 from it, a pipeline 5 is provided between the inner tank 2 and the outer container 3. A rigid connection of the pipeline 5 to both the inner tank 2 and the outer container 3 would, however, have the consequence that thermal changes in length of the inner tank 2 in relation to the outer container 3 would greatly impair this connection. For this reason, the pipeline 5, together with a cladding tube 6, is designed as a pipe lead-through module 7, which is described in detail below. According to FIG. 1, three pipe lead-through modules 7 are provided in the cryocontainer 1. The pipe lead-through module 7 arranged at the top in the installed position is used as a filling line and the two pipe lead-through modules 7 arranged at the bottom in the installed position are used as liquid extraction lines. The pipe lead-through module 7, however, is not restricted to these exemplary embodiments, but can also be used, for example, as a heat exchanger feed line or heat exchanger discharge line.

The pipe lead-through module 7 is formed in that the pipe 5 is at least partially received in the cladding pipe 6. The cladding tube 6 projects completely into the inner tank 2 and is rigidly connected to the inner tank 2 at a first cladding tube end 8, for example welded. As shown in FIG. 2, the cladding tube 6 has a stiffening ring 9 at the first cladding tube end 8, which makes it easier to weld the cladding tube 6 to the inner tank 2. The stiffening ring 9 can also be formed by a thickening of the cladding tube 6, so that the attachment of a separate stiffening ring 9 can be omitted.

It can also be seen from FIG. 1 that the pipeline 5 is rigidly connected to the outer container 3 at a first pipeline end 10, for example is welded. As shown in FIG. 2, the pipe 5 has a welding socket 11 at the first pipe end 10, which facilitates the welding of the pipe 5 to the outer container 3. Furthermore, the first pipe end 10 can preferably be equipped with an internal thread in order to more easily pull it out of the cladding tube 6 for a welding process with the outer container 3. Part of the pipeline 5 is guided between the outer container 3 and the inner tank 2 and the remaining part protrudes into the inner tank 2, where it is received in the cladding tube 6.

The pipeline 5 has a second pipeline end 12 within the inner tank 2 and the cladding tube 6 has a second cladding tube end 13. The pipeline 5 and the cladding tube 6 are rigidly connected to one another at the second cladding tube end 13, for which purpose the cladding tube 6 has an end plate 14 in this area may have. The second pipeline end 12 can either open into the end plate 14 or outside this, when the pipeline 5 is passed through the end plate 14.

The pipeline 5 and the cladding tube 6 are spaced apart from one another within the pipe lead-through module 7, so that there is a spacing space 15 between them. As in the intermediate space 16, this spacing space 15 lies between the inner tank 2 and the outer container 3 a vacuum to achieve thermal insulation. The spacing space 15 is connected, for example, to the aforementioned intermediate space 16. Alternatively, the cladding tube 6 could also comprise a plate at the first cladding tube end which terminates with the pipeline 5, so that the spacing space 15 is sealed off from the intermediate space 16.

According to the invention, the pipeline 5 and the cladding tube 6 each have a kink 17, 18 in an area between the first and the second cladding tube ends 8, 13. The pipeline 5 can thus have a first section 19, the kink 17 and a second section 20 and the cladding tube 6 can have a first section 21, the kink 18 and a second section 22. The first section 19 of the pipeline 5, which has the welding socket 11 and is connected to the outer container 3, and the first section 21 of the cladding tube 6, which has the stiffening ring 9 and is connected to the inner tank 2, are arranged essentially coaxially. This also includes deviations that occur in the context of thermal changes in length and deviations as a result of manufacturing tolerances, which can be caused on the one hand by the pipe penetration itself and on the other hand by the container, the inner tank suspension, pressure vessel bottoms, etc. The second section 20 of the pipeline 5 and the second section 22 of the cladding tube 6, which are each connected to one another, are also arranged essentially coaxially, apart from deviations which occur due to thermal changes in length and manufacturing tolerances.

The kink 17 in the pipeline 5 can be realized, for example, by a bent section of the pipeline 5, so that the pipeline 5 can continue to be manufactured in one piece. Alternatively, the first section 19, the kink 17 and the second section 20 of the pipeline 5 could be manufactured separately and connected to one another, e.g. welded. Both of these embodiments can also be used for the first section 21, the bend 18 and the second section 22 of the cladding tube 6.

The kinks 17, 18 can be designed such that the first sections 19, 21 of the pipeline 5 or the cladding tube 6 at an angle of 30 ° to 150 °, preferably from 70 ° to 110 °, particularly preferably 90 °, to one second section 20, 22 of the pipeline 5 or of the cladding tube 6. In the example shown in FIGS. 1 and 2, the kinks 17, 18 form an angle of 90 °.

FIGS. 1 and 2 also show that the pipeline 5 has a functional section 23 which is located inside the cladding tube 6. As shown, the pipeline 5 is designed as a bellows tube, in particular a metal bellows tube, via the functional section 23, which the pipe 5 helps in deformation due to thermal changes in length by reducing the stresses that occur. Alternatively, the pipeline 5 can be provided with a thinner wall thickness over the functional section 23 than the wall thickness of the pipeline 5 outside the functional section 23. The thinner wall thickness can also be realized by a wall thickness profile. A plurality of functional sections 23 within the cladding tube 6, each with the same or different properties, can be provided. The bellows tube, the metal bellows tube or the thin wall thickness can also each be provided with a braid wrap so that the capacity of the pipeline 5 to absorb high internal pressures can be improved.

FIG. 3a shows how a thermal siphon is formed according to the prior art. In the space 16 between the inner tank 2 and the outer container 3 of a cryogenic container 1, a pipeline 24 with an elevation 25 of height h is provided. If fluid flows through this pipeline and the valve 26 is then closed, fluid is initially in the liquid state in the entire pipeline 24. As shown in FIG. 3 b, due to the temperature at the outer container 3, which is higher than that of the fluid, a gas bubble 27 forms in the pipeline 24 and is held by the elevation 25 near the outer container 3. The gas bubble 27, in combination with the elevation 25, prevents the liquid phase 28 from flowing further in the direction of the outer container 3, whereby the gas bubble 27 can contribute to the thermal insulation of the fluid 4 from the outer container 3, or a constant flow and evaporation of the liquid phase and the associated Heat entry into the inner tank can be prevented.

With the pipe lead-through module 7, a thermal siphon is achieved at the same time for improved thermal change in length, without having to provide a complicated construction as in the prior art with a specially provided elevation 25 in the space 16.

According to the invention, the pipe lead-through module 7 with an already existing bend 17, 18 is installed in the cryogenic container 1 in such a way that the pipe lead-through module 7 acts as a thermal siphon in an operating position of the cryogenic container 1. For example, this can be achieved in that the first pipe section 19 connected to the outer container 6, starting from its connection point with the outer container 3, has a negative slope relative to the horizontal. Alternatively, the first pipe section 19 connected to the outer container 6, starting from its connection point with the outer container 3, can have a positive slope relative to the horizontal, so that the Kink 17 lies above the junction of the pipeline 5 with the outer container 6. In this case, however, the second pipe end 12 should open below the connection point between the pipe 5 and the outer container 6. The axis of the pipeline 5 does not have to lie in a normal plane of the container, but can also run obliquely to it.

Furthermore, as an alternative, the pipe lead-through module 7 could also be installed in a different position, for example if the pipe lead-through module extends entirely or partially above a nominal level F. In principle, a person skilled in the art can easily determine a suitable installation position of the pipe penetration module 7, so that the pipe penetration module 7 acts as a thermal siphon.

Thus, by suitable positioning, one and the same pipe lead-through module 7 can be attached to the entire circumference of the inner container regardless of the purpose of the pipe lead-through module 7, wherein the pipe lead-through module 7 can be used as a thermal siphon.

FIG. 4 shows an alternative embodiment of the pipe lead-through module 7 from FIG. 2, the same reference symbols denoting the same elements. In this embodiment, the pipeline 5 does not have a functional section 23, but the cladding tube 6 has a functional section 29. This functional section 29 can either be designed as a bellows tube, as shown. Alternatively, the cladding tube 6 could have a thinner wall thickness over the functional section 29 than outside the cladding tube 6. In both embodiments, the cladding tube 6 can have an axial stiffening 30 that spans the functional section 29. For example, two stiffening rods running parallel to the cladding tube 6 can be used for this, which are located on opposite sides of the cladding tube 6. The stiffening rods can for example be welded on the one hand to the end plate 14 and on the other hand to an intermediate plate 31, which in turn is attached to the rigid part of the cladding tube 6. The reinforcement 30 should be designed in such a way that it prevents the cladding tube 6 from being compressed in the axial direction and enables bending or kinking in the radial direction.

Regardless of whether the functional section 23, 29 is provided on the pipeline 5 or on the cladding tube 6, the pipeline 5 or the cladding tube 6 is designed to be more flexible over the functional section 23, 29 than outside of the functional section 23, 29, which, as already explained, for example can be achieved by a bellows pipe or a thinner wall thickness. Due to the flexibility of the functional section 23, 29, the pipe lead-through module 7 can more easily absorb bending stresses. Depending on the embodiment, the pipeline 5 or the cladding tube 6 can have one or more functional sections 23, 29. In addition, both the pipeline 5 and the cladding tube 6 can have one or more functional sections 23, 29.

Claims

Expectations:

1. Pipe feed-through module (7) for a cryogenic container (1) which has an inner tank (2) and an outer container (3) which is vacuum-insulated from this, the pipe feed-through module (7) having a jacket tube (6) and an at least partially in the jacket tube (6) accommodated pipeline (5), characterized in that the pipeline (5) passes through a first cladding tube end (8) of the cladding tube (6) so that a first pipeline end (10) of the pipeline (5) is rigid with the outer container (3) and the first cladding tube end (8) can be rigidly connected to the inner tank (2), the pipeline (5) and the cladding tube (6) being rigidly connected to one another at a second cladding tube end (13), and the pipeline (5) and the Cladding tube (6) each have a kink (17, 18) in an area between the first cladding tube end (8) and the second cladding tube end (13).

2. Pipe bushing module (7) according to claim 1, wherein the kinks (17, 18) are designed such that a first section (19, 21) of the pipeline (5) or the cladding tube (6) at an angle of 30 ° to 150 °, preferably from 70 ° to 110 °, particularly preferably 90 °, to a second section (20, 22) of the pipeline (5) or the cladding tube (6).

3. Pipe bushing module (7) according to claim 1 or 2, wherein the pipeline (5) or the cladding tube (6) over at least one functional section (23, 29) is more flexible than outside the functional section (23, 29).

4. Pipe lead-through module (7) according to one of claims 1 to 3, wherein the pipe (5) has a thinner wall thickness over at least one functional section (23) than outside the functional section (23) or wherein the pipe (5) over at least one functional section ( 23) is designed as a bellows tube, the functional section (23) being at least partially within the cladding tube (6).

5. Pipe bushing module (7) according to one of claims 1 to 4, wherein the cladding tube (6) has a thinner wall thickness over at least one functional section (29) than outside the functional section (29) or wherein the cladding tube (6) over at least one functional section ( 29) is designed as a bellows tube.

6. Rohrdurchfühmngsmodul (7) according to claim 5, wherein the functional section (29) is spanned by an axial stiffener (30), which is preferably formed by two stiffening rods running parallel to the cladding tube (6), which are located on opposite sides of the cladding tube (6 ) are located.

7. Pipe bushing module (7) according to one of claims 1 to 6, wherein the pipe (5) at the first pipe end (10) has a welding socket (11) for connection to the outer container (3).

8. Pipe bushing module (7) according to one of claims 1 to 7, wherein the cladding tube (6) at the first cladding tube end (8) has a stiffening ring (9) for connection to the inner tank (2) and the stiffening ring (9) preferably by a thickening of the cladding tube (6) is formed.

9. Pipe bushing module (7) according to one of claims 1 to 8, wherein the cladding tube (6) at the second cladding tube end (13) has an end plate (14) for connection to the inner tank (2).

10. Pipe bushing module (7) according to one of claims 1 to 9, wherein the pipe (5) is equipped with an internal thread at the first pipe end (10).

11. Pipe bushing module (7) according to one of claims 1 to 10, wherein the space (15) between the pipe (5) and the cladding pipe (6) is designed such that the first pipe end (10) is at least one wall thickness of the outer container (3) can be displaced into the cladding tube (6) for an assembly process.

12. Cryogenic container (1), comprising an inner tank (2), a relative to the inner tank (2) vacuum-insulated outer container (3) and a pipe lead-through module (7) according to any one of claims 1 to 11, wherein the first pipe end (10) is rigid with is connected to the outer container, preferably welded, the first cladding tube end (8) is rigidly connected to the inner tank (2), preferably welded, and the cladding tube (6) protrudes into the inner tank (2).

13. Cryogenic container (1) according to claim 12, wherein the pipe bushing module (7) is connected to the cryogenic container (1) in such a way that the pipe bushing module (7) acts as a thermal siphon in an operating position of the cryogenic container (1).

14. Cryogenic container according to claim 12 or 13, wherein the pipe lead-through module (7) is guided through a jacket of the cryogenic container.